1. Field of the Invention
The present invention relates to a video printer and more particularly to an apparatus for holding a receiver sheet in a video printer.
2. Background
Generally the video printer is designed to produce a full-colored image on a dye-absorbing receiver sheet by thermally transferring three different colored dyes, including yellow (Y), magenta (M) and cyan (C), in response to video signals. Namely, as shown in FIG. 1, the three different colored dyes of Y, M and C sequentially disposed on a ribbon 1 are heated by thermal print head 4 and transferred to the receiver sheet 3 fixedly supported on a platen drum 2 and rotated therewith.
An apparatus for holding the receiver sheet to the platen drum is disclosed in U.S. Pat. No. 4,815,870, as shown in FIG. 2. In this device, when the receiver sheet 3 is supplied through a supply guide chute `A`, a bracket 7 is pivoted clockwise about a pivot 7b along the exterior camming surface of a first cam 5a, so that an urging portion 7c of the bracket 7 urges contact portion 6a of a clamp 6 counterclockwise. As a result, spring 9 is expanded and the clamp 8 moved beyond the peripheral surface of the platen drum 2 so as to receive the receiver sheet 3. Subsequently, when the cam follower 7a of the bracket 7 moves over the camming surface of the cam 5a and the urging portion 7c of the bracket 7 no longer applies a force to the contact portion 6a of the clamp 6, the resilient force of the spring 9 causes the clamp 6 to be rotated clockwise so as to clamp the receiver sheet 3 against the platen drum 2.
When the receiver sheet 3 is discharged through the discharge guide chute `b` after completion of the printing, the platen drum 2 is rotated in the direction opposite to that of printing. As a result, the clamp 8 is displaced from the peripheral surface of the platen drum 2 to release the receiver sheet 3 as the bracket 7 moves along the exterior surface of the second cam 5b.
With such a conventional printer the supply guide chute `A` and discharge guide chute `B` are separated by the platen drum 2, as shown in FIG. 2. As a result, the overall size of the printer is relatively large. In addition, in order to discharge the receiver sheet it is necessary that the platen drum be rotated in the direction opposite to the printing direction. Moreover, all three of the different colored dyes must be transferred to the receiver sheet before reversing the platen drum 2 in order to discharge the receiver sheet, thus increasing the printing time.